In recent years, there is a dramatically increasing demand for mobile data traffic along with the popularization of the mobile Internet and smart cellular phones, and indoor data services take a significant proportion thereof. Indoor and hotspot data services are characterized by typical immobility or very-low-speed mobility (nomadic mobility) of subscribers with a low mobility requirement; and on the other hand, the data services are generally Internet services based on Internet Protocol (IP) with a unified Quality of Service (QoS) requirement far below a QoS requirement of telecommunication-level services. Since a traditional cellular mobile communication system is generally designed for the high-speed mobile telecommunication-level services with seamless switching, it may be inefficient and costly when bearing the large-traffic low-speed IP data packet services. In view of this, cellular mobile network operators have to find out a low-cost high-capacity solution applicable to radio data access indoor and in a hotspot area. At present there are generally the following two solutions.
A first solution is a solution based on a Wireless Local Area Network (WLAN) in an unlicensed frequency band, for example, a method of branching a hotspot data service in a Wireless Fidelity (WiFi) system. In this solution, a WLAN system and a 3G system are generally coupled loosely to perform authentication and charging in a core network through the 3G system and to have radio network access through the WLAN.
The use of the foregoing architecture to cover the hotspot area can better branch the data service, but the use of the two different standard frameworks and systems results in poor experience of subscribers and the network can not provide the subscribers with a QoS guaranteed service due to the limitation of the WLAN radio access technology; and also link quality is susceptible to interference from other systems.
A second solution is a solution in which a demand for data service traffic indoor and in a hotspot area is met based on a femto cellular eNB (also referred to as a home eNB or Femto). This solution is characterized by a shorter coverage distance indoor and a smaller number of subscribers. Specifically the home eNB has transmission power comparable to a cellular phone terminal, typically below 23 dBm, and the number of subscribers typically ranges from 8 to 20. The home eNB has a lower cost and more flexibility of deployment than an indoor coverage system and a micro eNB, and functions to enhance data service experience of the subscribers indoor to some extent. However a drawback thereof lies in that the home eNB is not optimized for the low mobility or nomadic mobility characteristic of the data service indoor, and taking the Long Term Evolution (LTE) Femto system as an example, the LTE Femto system substantially adopts the entire protocol architecture and interface design of the LTE system with the support of a UE handover and is complex to implement despite reductions in capacity and power of the eNB and consequently still highly expensive. Moreover in the home eNB network, the majority of communication processing flows of UEs have to be controlled and managed by the 3rd Generation Partnership Project (3GPP) core network, and data packets of the UEs for an access to the Internet and other external networks have to be forwarded by the 3GPP core network, thus bringing considerable signaling and data loads to the core network. This architecture also makes the home eNB network fail to be optimized in view of the characteristics that the subscribers indoor and in the hotspot area locally access to and visit the external networks.
In view of the issues of access and coverage indoor and in the hotspot area, the architecture of the LTE Femto system is complex and costly, and the communication process of the UEs may bring a considerable load impact on the 3GPP core network, but the WLAN technology fails to provide the UEs with telecommunication-level QoS guaranteed services despite its simple network deployment.